CVE-2026-97753: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft 365 Apps for Enterprise

This vulnerability, identified as CVE-2026-97753, is a heap-based buffer overflow in Microsoft Office Excel, part of Microsoft 365 Apps for Enterprise. It enables remote code execution by an unauthorized attacker over a network. The CVSS 3.1 base score is 8.8, indicating high severity, with attack vector network, low attack complexity, no privileges required, and user interaction required. The vulnerability affects multiple specific versions of Microsoft 365 Apps for Enterprise around version 16.0. Microsoft has released an official fix, and the vendor advisory is available at the Microsoft Security Response Center update guide.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code remotely on the affected system, potentially leading to full compromise including confidentiality, integrity, and availability impacts. The vulnerability requires user interaction but no privileges or authentication, increasing its risk in networked environments. No known exploits are reported in the wild currently.

An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft for Microsoft 365 Apps for Enterprise as detailed in the vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97753. Since this is a cloud service, Microsoft manages remediation for the cloud-hosted components. Ensure that all affected versions are updated to the fixed versions as per the advisory.